I'm an SSD nay-sayer. More so in laptops than desktops.
Not because I doubt the speed is "noticeable". But because with some exceptions like the video files example, it isn't significant.
Sleep mode is faster boot than an SSD, and costs nothing.
Faster anti-virus scanning ? That's worth how much ? $0.
Anyway the bottom line is-
1. They cost too much for what they deliver.
2. They aren't proven to be reliable enough as primary storage. Which means they require the use of hard drives anyway, so at best they are redundant.
3. For a laptop they require compromises in storage space/ or optical drive functionality.
For some purposes I can see SSDs make sense, for a boot drive in a desktop, or for a special purpose notebook.
I just don't agree with them being universally recommended.
Not suitable in a notebook? Madness!
One of the best advantages to owning an SSD in a notebook is their incredibly low idle power consumption.
What's more important is that that they're invulnerable to shock. If you've ever travelled with a laptop for work on a daily basis, you'd know that shock is a big factor when it comes to the endurance of laptop drives. Having a drive built of no moving parts completely eliminates that issue.
I don't usually say this, but you really couldn't be more wrong. Having an SSD in a laptop is probably the best thing you can EVER do for it--and for reasons completely unrelated to performance.
With regards to your other points:
1) Nobody is recommending them to absolutely everyone. But if you have the money, more often than not, you likely won't see a better bang for your buck.
2) Really? Failure is not an SSD exclusive issue. Have you ever had a drive fail? Have you ever lost work-critical info due to data loss? I know a few people that have, myself included. NOTHING is reliable enough for primary storage. That's why it's sensible to back things up regardless of your primary storage format.
3) Not a universal truth. I do more with my laptop than most, and I require only 180 of my 250GB Intel 510. Of course I have external storage, but that was the case with my larger HDDs too. I just don't like carrying EVERYTHING with me. I'll chalk this one up as an inaccurate assumption.
As for copying of video files, have you ever tried doing something on your computer when you HDD is being fully utilized in a copy operation? It's pretty painful--Even for the best HDDs, as they're only capable of so much multitasking. They essentially need to stop copying data to fetch what you need. This slows down both operations and can really slow down your computing experience regardless of your computer specs.
However, SSDs simply don't have that limitation. With 20-100 times the IO capability of a hard drive so the not only do they copy much faster, but their absence of any seek time allows all that to happen without really reducing latency.
Anyone who doesn't believe in an SSD's ability to transform your computing experience either doesn't do that much storage bottlenecked stuff, or simply doesn't understand how SSDs can benefit them.