Lots of reasons.

I dislike it because it fails at everything it tries to do. Look how over time the goalposts have changed on Bitcoin’s “purpose” or “value”.

It fails at being a currency -> means of exchange because the fees are too high and transactions are too slow.

It’s incredibly inefficient and wasteful. Cryptographic mining calculations are an excessive environmental cost.

It’s volatility makes it a poor store of value. If something’s only purpose is to store value, I don’t want it to suddenly drop 20%, 50% of its value overnight. I want it to beat inflation, which Bitcoin seemingly does ... but so does literally anything else by the definition of inflation ....