This entire safe/unsafe debate doesn't make much sense. You're investing your money into someone's product in order to accomplish something--usually make more money.
An investment is never safe, that's the whole point. You willingly "give up" your money by investing into something else in hopes of it doing well and making you even more money sometime in the future. There's nothing certain about that no matter what sort of investment we take.

Perhaps a better question would be whether it's really that easy to make money on ICOs. Of course.. it depends.
In general, you can make a shit ton of money even on really bad project--considering you're aware and know when to get rid if it. It's probably not the best strategy though. Also, while many of the blockchain projects are indeed very different from the usual business startups, they have something in common. That's the fact that most new business fail. Even the best ones can fail, and often will.

So no, not every ICO is a scam, some of them are, but if you do due diligence, you should be able to find solid projects, with good teams and support behind them. Again, that is no guarantee of anything.

Another thing to consider is something I've been paying a bit more attention to lately. I've always found a bit strange how many people there are who dump their tokens as soon as they possibly can. It's not like you win a jackpot with each sale, but everytime, those people are there. So I had dug into it a bit more as I felt there was something I didn't know. And if there's one important realization I made, it's this: people have no idea how many investors are making money off of them without them knowing. By each public token sale or even pre-sale, you already paying for their investments which they got on better terms.
Most often those are the big players, hedge funds, etc. who get better prices, but you don't need to be an accredited investor at all. The whole Silicon Valley is pretty much build on this...
You invest under something bigger-- you form groups with other investors and, as a result, your buying power grows. That's how you get the good deals, it doesn't need to be anything formal or official. Might not beat the hedge-funds, but you'll beat the public solo investor, in some cases by a lot.  The thing is, those groups are often private and it's hard to find them. The YouTuber from the CoinMastery channel mentioned this some time ago and it made perfect sense when he was talking about it. I've recently discovered just one such group https://cryptosyndicate.org, where they do this exact thing. I can definitely recommend that one, but the deals don't come too often. Not if you plan on investing into multiple ICO's each week.

The best part about this "collective buying" is that if the bonuses are big enough, you can make some really easy money by selling asap, no matter the coin really. If the bonus gets you 50% more tokens, it will probably be the easiest 2x of your life. That CoinMastery YouTuber said he sees future in this exact thing and I tend to agree. It's kind of the same concept as the Angel List concept of Naval Ravikant, but you don't really have to do anything , just get in the group and wait for good enough

You should definitely make your own picture so don't take anything I said as advice. Just what I think..