Thanks for asking--I'll try to keep it brief (so as not to bore), and my apologies if I am retreading stuff you already know, but I'll have to do some lead-in to explain why I care about this at all.

Why past participles?--and why I love them:

Starting with a couple of example sentences that could help differentiate the "simple past" form versus the "present perfect" form that uses the past participle:

• I saw a shooting star last night.
• I have not seen a shooting star.

In the first example, the time mentioned is "last night"-- a time period that in the mind of the speaker is finished or closed.

In the second, there is no time frame mentioned, but we intuitively understand that it is making reference to a period of time that is unfinished or still open--in this case that period is "in my life."

I really appreciate the nuance that a change in verb form can impart, and so elegantly done!

Participles in telling stories

When it comes to telling stories to each other we almost exclusively keep the main actions in the sequence of events in simple past forms, eg.:

• I woke up.
• I got a shower.
• I ate breakfast.
• I couldn't find my car keys.
• I had to take the bus to work.

But what if I wanted to have a little twist in the story where I make reference to stuff that happened before my narrative? In English we've got this great trick up our sleeves. I could use the past perfect, formed by had + past participle, eg:

1. I couldn't find my car keys. Little did I know that my wife had accidentally dropped them into the laundry basket. So I had to take the bus...

Simple, clean, elegant, and provides a satisfying twist :) Otherwise I would have to tell it like:

2. My wife accidentally dropped my keys into the laundry basket. I woke up. I got a shower....

Or like this:

3. ...I couldn't find my car keys. Earlier my wife accidentally dropped my keys in the laundry basket, but I didn't know that at the time. I had to take the bus to work.

I guess all are valid, but I certainly find option 1 the nicest. Option 2 has spoilers. Option 3 is what many other languages do.

Verbs and simplification in languages

If I recall from my dabbling in linguistics, there's a tendency among most languages to become simpler in terms of their grammar over time. Most English verbs are now "regular," and you can make the simple past and past participle just by adding -ed to the end of the verb, eg.:

• yell - yelled - yelled
• ask - asked - asked
• smile - smiled - smiled

But among our oldest and most common verbs we've got bunches of "strong/irregular" verbs, eg.:

• go - went - gone
• take - took - taken
• see - saw -seen

These are the verbs that people are changing in spoken American English at present. People are "regularizing" the past perfect forms by dropping the past participle and using had + simple past. I know it mainly comes down to linguistics drift and personal choice, but I appreciate that these irregular participles have purpose (by being a part of the perfect tenses, and the nuance they can create), and history. Moreover, I think having greater mastery of these forms in your speech and writing helps make reading texts written in English before the end of the 20th century so much easier.

Long story short: people can and will speak English however they want. No big deal. But in the case of excising the irregular past participles from English, I'll hold on to what I was taught and grew to love about English grammar.