Yes always

You’re better off ignoring them.

no you should reject based on nothing.
the great decent guys that say hi can be just shy and they can be amazing people. but it's great for them that shallow judgemental bitches just disregard their messages so you may be doing a favour to many

In my honest opinion, I think is okay not to reply to some messages because there could be some that were not interested in. We do have an option to answer them.
It Happened to me also, that's why I give up on Dating Sites lol.

I think I'd only respond to the ones I think might be interesting

Always reply at least ones. Because that's the polite thing to do. Even to just hi.

No definitely not - it's too much effort, just respond to those that appeal to you.

Nah... no need to, many will still think you're interested just by replying to them and wont give up

It's a dating site. I would only carry on conversation with a possible romantic lead. The rest I'd either ignore or respond with a simple "thanks but no thanks" type message.

I think you're doing the right thing.At least you're being honest to them.

I find that responding leads people on. It gives false hope. I just ignore even though many say they hate it, I’m saving us both time.

be blunt and tell them you're dead inside

It's probably best you don't respond if you aren't interested. Like you said it can create problems later on you don't want. I gave up dating sites. A lot of fakes on them.

If it's obvious that it won't lead anywhere don't answer.
Or better : block them. Like in my About me.

I used to reply to all. But learned ignore is the best way. It's an accepted form of rejection with online dating