Capacity vs Scalability

Let’s talk about terminology.

Capacity: The number of transactions that can be processed on the network.

Scalability: Capability of the network to handle a growing amount of work.

1) A 2MB hardfork is a capacity increase but not a scalability improvement.
2) Segregated Witness is a capacity increase and a scalability improvement.
3) Monero has no block size limit and thus a higher capacity than Bitcoin, however its TXO pool is unpruneable, its blockchain would grow faster at same usage, and its transactions take more computational effort to validate, so it doesn’t scale as well as Bitcoin.

Lightning network is not a sidechain

The Lightning network is not a sidechain.

A sidechain relies on its own blockchain which is coupled to the Bitcoin blockchain via a two-way peg.

On the other hand, Lightning network consists of native Bitcoin 2-of-2 multisig transactions.

When two Lightning nodes open a payment channel, they both send funds to one multisig address and each provides the counterparty with a pre-signed exit transaction. If a party wants to resolve the payment channel, they can unilaterally add their own (the second) signature and send the transaction to the Bitcoin network for confirmation.

However, it is more efficient to update the balance of the payment channel repeatedly by exchanging new exit transactions. The updated exit transactions simultaneously invalidate the previous exit transaction. Whenever anyone wants to get out or tries to cheat (by using an invalid exit transaction), the exit transaction is moved to the Bitcoin blockchain for arbitration. Newer exit transactions then override older ones1.

So, while Lightning Transactions can happen off-chain, they can be put on-chain anytime.

What color is that Merkle root?

Core and Classic share the same long-term goal: To develop Bitcoin from a lab experiment to a revolution of global money systems.

However, they are advocating different short-term approaches due to diverging perception of the current situation.
If we imagine ourselves looking back from a 2040 that achieved this goal, would we care whether we first implemented Segregated Witness and then increased the blocksize1, or vice versa?

Neither approach appears to promise catastrophic failure, although each side makes it out that the other is more likely to do so.
This is the point, where people usually would agree to disagree and split a project to follow their strategies on separate paths, but other than most free software that can be run in isolated instances of varying flavors, Bitcoin is unique in that running divergent versions could cause the network to split. A split would severely impact the value of the whole network and especially the potential value of the opposite sister projects.

The Bitcoin project is complex. It’s many-faceted and points of view are colored by the heterogeneous interests of the diverse invested parties. It is hard to grasp the project’s challenges in its entirety. While developers on both sides are challenged to take the broader picture into account for their strategy, the community tends to pick out easy-to-grasp bits and pieces to debate. – This behavior is commonly coined as bike-shedding.

That is not to say that the community doesn’t contribute to said issues, or that the issues were irrelevant. Rather, it causes those issues to receive magnitudes more attention and effort than would be efficient.

Which raises the question: why do we waste all the involved parties’ time, and make all our lives miserable by emotionally arguing over an issue that has the importance of the bike shed’s color at the design review for a moon rocket landing pad?

The developers are more invested in this than you. If not for any other reason, you can have a little faith in them because they won’t aim to disintegrate their own work and the fruits of labor of the past six years.

So, please:
Keep being so engaged and contribute! Keep track of facts and assumptions. Read up on things that seem odd, and ask questions about what remains unclear. Try to be open-minded, and don’t only read content that already confirms your previous opinion. Yet, don’t waste people’s times by forcing them to repeat their points endlessly.