Many are of the opinion that, if you are trying to make something beautiful, you shouldn't be using something like marquee anyways. that's all just opinion though. some people may like looking at it on a site and some may not. it's also not about what you like as a developer/designer but what will appeal to your target audience. if using something like marquee will make the user experience unpleasant for your audience then you're potentially losing views and/or money. is it really worth it?
Refer this thread ,Where one of the fellow sololearner @Maz has explained about marquee tag beautifully.
The major problem with marquee tag is portability it's not interoperable
It's such a pity that they removed the <marquee> from the new standard, now you have to make more code to do the same. Now creative Web Designers have to be also programmers instead focusing only on beautiful designing. Someone disagree?
They are apparently removing marquee from HTML5.
It may not work on many browsers, so youre site will not look right on every browser.
But we dont need <marquee> now with CSS or JS we can do the same thing! So thats why marquee isnt needed.