Can $ETH short? Technically speaking: Yes

But will I short, or even shout about it in the community?

The answer is no.

In addition to technical aspects, trading essentially means making money off the opposing party.

If a large number of short positions with the same entry point and stop loss appear simultaneously, and the stop loss is right at 3000. Will the market maker eat this liquidity?

I believe they will!

Market makers need money to push up prices; is it for fun or to offload? I don't believe that.

If it were only about the technical aspects, then who would be losing money in this market?