They do that to keep cops, reactionaries, wreckers, and assholes out and to maintain ideological consistency, which is actually important if you want an effective party.
Yes, it's a conscious decision to trade size for all of these benefits. But a party the size of the PSL is ineffective by default; they've struck the wrong balance.
How? By what process?
Demonstrating that mass collective action can produce material improvements could catalyze bigger changes in the same direction. There's also the idea that taking the boot off the neck of workers, at least a little bit, can make non-electoral strategies easier.
Yes, it's a conscious decision to trade size for all of these benefits. But a party the size of the PSL is ineffective by default; they've struck the wrong balance.
Demonstrating that mass collective action can produce material improvements could catalyze bigger changes in the same direction. There's also the idea that taking the boot off the neck of workers, at least a little bit, can make non-electoral strategies easier.