The previous time I've posted in this thread seems to be four years ago, after which I've given this topic some thought every now and then. I'd say there's also another main reason why eurobeat so rarely comes across as depressing, in addition to the tempo: the supplementary nature of lyrics.
The focus being on composition and arrangement, eurobeat lyrics' primary function is typically to carry the melody and to sound good. Consistency is not required. The aforementioned
Yes I Will, for example, would fit the bill of a sad love story, if only it was able to make up its mind what's actually happening. "
I'll never leave you"... but then, "
I will give up on you"? Wasn't it
him who "
got to decide"? I do understand the concept of stream of consciousness and that people tend to get incoherent when faced with conflicting emotions but yet, this is more the norm than an exception.
I'd be surprised to meet somebody who listens to eurobeat because of the lyrics

Conversely, in (especially certain types of) pop, it's not unusual at all for a song to gain popularity because of its text. Having said that, every now and then you come across eurobeat lyrics that tell coherent
and depressing stories. There are also sad love stories that make sense. One of my favorites is Denise's Burning Like a Flame
(even though personally I think jealousy is just stupid in general) with its powerful statement "
I was dying inside me, jealousy is a killer / You killed everything in me".
Daniel's
Frontal Impact represents another kind of a dramatic story with a strong atmosphere. Without the opening line I'd be sure it was about how time slows down in your mind when you're in a traffic accident. My favorite line is the last of the chorus, "
Seems I'm watching just myself that dies", possibly refering to an out-of-body experience.
A more random find, Rick Wild's
Fight for Your Life is quite depressing as well: "
He looks up at the sky and he shouts 'why' / Then the police shoot him down / And before he dies, he stumbles and cries".